DGMGRL> show configuration;

Configuration - dgc

  Protection Mode: MaxProtection

  Databases:

    atest1 - Primary database

    atest2 - Physical standby database

Fast-Start Failover: DISABLED

Configuration Status:

SUCCESS

DGMGRL> switchover to atest1;

Performing switchover NOW, please wait...

Operation requires a connection to instance "atest" on database "atest1"

Connecting to instance "atest"...

Connected.

Operation requires startup of instance "atest" on database "atest2"

Starting instance "atest"...

ORA-: obsolete or deprecated parameter(s) specified for RDBMS instance

ORACLE instance started.

Database mounted.

Database opened.

Operation requires shutdown of instance "atest" on database "atest1"

Shutting down instance "atest"...

Unable to connect to database

ORA-: Connect failed because target host or object does not exist

Failed.

Warning: You are no longer connected to ORACLE.

Please complete the following steps to finish switchover:

    shut down instance "atest" of database "atest1"

    start up instance "atest" of database "atest1"